Known in the art is a concentrator (U.S. Pat. No. 4,157,951), comprising a hollow vertically extending casing having a pipe for supplying a separating fluid provided adjacent to a bottom end of the casing, a pipe for discharging the separating fluid and light fraction provided adjacent to a top end of the casing, and a pipe for discharging heavy fraction provided adjacent to the bottom end of the casing.
The material being handled is charged into the concentrator together with the separating fluid. An upward flow of the material being handled is created in the casing between the pipe for supplying the separating fluid and the pipe for discharging light fraction owing to the supply of the separating fluid. Light fraction is moved upwards by the flow of the material being handled and is discharged through the pipe for discharging light fraction and heavy fraction of a higher specific gravity is concentrated in the bottom part of the casing and is discharged through the pipe for discharging heavy fraction.
The prior art concentrator is suitable for the separation of classified concentrated material. Only a laminar upward flow of the material being handled is created in the casing of the concentrator so that a part of heavy fraction cannot be suspended. This lowers the possibility of preparing a high-grade concentrate. The prior art concentrator does not make use of the effect of friction between particles of the material being handled and the inner surface of the casing, and fine particles of heavy fraction are lost from the concentrator with the upward flow of the material being handled.
The prior art concentrator does not allow high degree of concentration of heavy fraction particles to be achieved in the pipe for discharging heavy fraction, nor does it ensure the control of the degree of concentration of particles of heavy fraction so that efficiency of separation of the material being concentrated is rather low.
Also known in the art is a concentrator (GB,A, No. 2003756), comprising a hollow cylindrical casing which extends in an inclined position having a separating partition which divides the casing into two conjugated chambers communicating with each other through a pipe provided in the partition and extending coaxially with the longitudinal axis of the casing. A top end of the casing has a pipe for supplying a material being handled and a bottom end of the casing has a pipe for discharging heavy fraction. In addition, the casing is provided with an auxiliary tangentially positioned pipes for supplying and discharging a separating fluid and light fraction.
All the material being handled is in a turbulent flow and in a suspended state in the prior art concentrator so that high quality of separation of particles of heavy and light fractions cannot be ensured.
The prior art concentrator cannot ensure a high degree of concentration of heavy fraction particles in the pipe for discharging heavy fraction either, nor does it provide for the control of the degree of concentration of heavy fraction particles in concentrating various kinds of mineral raw materials.
The most similar to the invention is a concentrator (GB, A, No. 2164589), comprising an inclined elongated hollow casing for receiving a material being handled having a pipe for supplying the material being handled, a pipe for supplying a separating fluid and pipes for discharging light and heavy fractions of the material being handled.
This prior art concentrator involves the creation of a number of successive turbulent zones in which heavy and light fractions are separated. Fine particles of heavy fraction do not have time to move to the bottom of the concentrator and are lost together with light fraction. This does not allow hydrodynamic conditions of separation of fractions of the material being concentrated to be optimized and, in particular, a flow of the material being handled cannot be created with a local turbulence gradually turning to laminar flow accompanied by a wall boundary layer effect. The prior art concentrator does not make it possible to achieve a high degree of concentration of heavy fraction particles in the separating chamber and in the pipe for discharging heavy fraction, nor does it allow the degree of concentration of heavy fraction particles to be controlled during concentration of various kinds of mineral raw materials.
It is an object of the invention to enhance efficiency of separation of a material being handled into light and heavy fractions.